The objectives of this study are twofold. (1)\To isolate and identify new imino acids in crowngall tumors. In our preliminary experiments, we detected refractometrically large quantities of unknown acidic compounds in crown-gall tumors. The main component in some null-type tumors has been isolated and identified as N2-(1,3-dicarboxypropyl)-L-leucine which also exists as a cyclized (i.e., lactam) form, N-(L-1-carboxy-3-methylbutyl)-5-oxoproline. This compound was given the name leucinopine. Evidence also shows that N2-(1,3-dicarboxypropyl)-L-glutamine (glutaminopine) is the main component in some other null-type tumors. (2)\To study new imino acid synthases. Leucinopine synthase has been partially purified, and its characterization is in progress. Purification and characterization of glutaminopine synthase will also be carried out.